A series of laboratory and greenhouse experiments were conducted at the Environment, Natural Resources and Desertification Research Institute (ENDRI), National Centre for Research (NCR) and College of Agricultural Studies, Sudan University of Science and Technology (SUST), Sudan, to examine the efficacy of the fungus Trichoderma harzianum, culture age, inoculum type, application time, fungal extract, compost and bacterial strain on Striga hermonthica germination and sorghum infestation. The highest significant (P≤0.05) inhibition on S. hermonthica germination was obtained at 10 days by T. harzianum culture as compared to both controls. Application of all T. harzianum aqueous and ethyl acetate extracts concentrations significantly (P≤0.05) reduced S. hermonthica seed germination as compared to the corresponding control. T. harzianum inoculum extracted by ethyl acetate reduced germination by 97%. T. harzianum aqueous 100% induced germination during conditioning by 64 % in response to GR24 (0.1ppm). All types of T. harzianum inoculum (Autoclaved, culture and filtrate) significantly (P≤0.05) reduced germination, with application of T. harzianum culture filtrate gave the highest reduction on germination as compared to control and other inoculums. Application of the 3 inoculums at 2 hours reduced germination percentage more than at 4 hours. Filtrate and culture inoculums at 2 hours reduced germination by 79 and 68%, respectively. The combination of compost 100%+ T. harzianum + BMP+Flavobacterium reduced germination by 68%. The greenhouse results showed that the combination of compost plus BMP+ Flavobacterium gave lowest number of S. hermonthica emergence and the highest sorghum plant height. The combinations of compost with T. harzianum and with BMP+ Flavobacterium significantly reduced S. hermonthica dry weight, increased sorghum shoot and root dry weight insignificantly as compared to the control.
Int.J.Curr.Microbiol.App.Sci (2019) 8(3): 195-206 International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume Number 03 (2019) Journal homepage: http://www.ijcmas.com Original Research Article https://doi.org/10.20546/ijcmas.2019.803.027 Potential of Trichoderma harzianum as a biocontrol agent against Striga hermonthica in sorghum Mohammed M Hassan1*, Mona A Azrag2, Ahmed M.E Rugheim3, Rashida M.A Abusin4, Maria H Elnasikh1, Hanan I Modawi1, Magdoline M Ahmed1, Rania A Abakeer1, Awad G Osman1, Migdam E Abdelgani1 and Abdel-Gabar E Babiker1 Environment, Natural Resources and Desertification Research Institute, National Center for Research, Sudan Sudan Academy of Sciences (SAS), Sudan Landscaping and Arid Land Agriculture, Faculty of Agriculture, Omdurman Islamic University, Sudan Pests and Plant Health, College of Agriculture, Bahri University, Khartoum, Sudan *Corresponding author ABSTRACT Keywords Bacteria, compost, Culture, Fungi, Inoculum Article Info Accepted: 04 February 2019 Available Online: 10 March 2019 A series of laboratory and greenhouse experiments were conducted at the Environment, Natural Resources and Desertification Research Institute (ENDRI), National Centre for Research (NCR) and College of Agricultural Studies, Sudan University of Science and Technology (SUST), Sudan, to examine the efficacy of the fungus Trichoderma harzianum, culture age, inoculum type, application time, fungal extract, compost and bacterial strain on Striga hermonthica germination and sorghum infestation The highest significant (P≤0.05) inhibition on S hermonthica germination was obtained at 10 days by T harzianum culture as compared to both controls Application of all T harzianum aqueous and ethyl acetate extracts concentrations significantly (P≤0.05) reduced S hermonthica seed germination as compared to the corresponding control T harzianum inoculum extracted by ethyl acetate reduced germination by 97% T harzianum aqueous 100% induced germination during conditioning by 64 % in response to GR24 (0.1ppm) All types of T harzianum inoculum (Autoclaved, culture and filtrate) significantly (P≤0.05) reduced germination, with application of T harzianum culture filtrate gave the highest reduction on germination as compared to control and other inoculums Application of the inoculums at hours reduced germination percentage more than at hours Filtrate and culture inoculums at hours reduced germination by 79 and 68%, respectively The combination of compost 100%+ T harzianum + BMP+Flavobacterium reduced germination by 68% The greenhouse results showed that the combination of compost plus BMP+ Flavobacterium gave lowest number of S hermonthica emergence and the highest sorghum plant height The combinations of compost with T harzianum and with BMP+ Flavobacterium significantly reduced S hermonthica dry weight, increased sorghum shoot and root dry weight insignificantly as compared to the control 195 Int.J.Curr.Microbiol.App.Sci (2019) 8(3): 195-206 Introduction Weeds are the most universal of all crop pest, proliferating each year on every farm in Africa (Obuo et al., 1997) Striga hermonthica, S asiatica (L.) Kuntze and S gennerioides (Willd) Vatke are recognized as the largest biological constraint to food production in Africa The genus Striga comprises about 30 obligate root parasitic plants, commonly known as witch weed (Babiker, 2007; Spalak et al., 2013) Ejeta and Butler (1993) reported that sorghum production is constrained by many factors and one of the most serious threats is Striga Several strategies have been developed for control of parasitic weeds which include improved cultural practices, breeding using wild and cultivated germplasms as sources of resistance, the use of chemical fertilizer(or) and phosphate - based seed priming (Jamil,2012) Chemical control is inappropriate and nondiscriminatory putting human and animal health at risk, as well as contaminating the environment (David, 2001) Therefore the use of integrated management of control methods including biological control can offer an alternative approach to control parasitic weeds Fungi have received great attention as biocontrol organism against pest (Benitez et al., 2004) Regarding this, biological control using microorganisms (especially phytopathogenic fungi) showed high efficacy in controlling S hermonthica under controlled and field condition (Zahran, 2008) The bioagent Trichoderma harzianum is abundant in soil under all climates over different geographical regions It was known as efficient decomposers of various substrates, having rapid growth rates and antimicrobial properties Moreover, Celar et al., (2005) stated that Trichoderma spp can be used as plant growth promoting fungi They increase germination rate and percentage of emergence, plant height, leaf area and dry weight It was estimated that 90% of fungi utilized in biocontrol were Trichoderma strains (Benítez et al., 2004) Trichoderma can act indirectly, by modifying environmental conditions, promoting plant growth and induced plant defensive mechanisms and antibiosis, or directly, by mechanisms such as mycoparasitism, competition, enzyme activity (Vinale et al., 2008) Microorganisms can produce phytohormones, such as indole acetic acid (IAA) and cytokinins which have a positive effect on plant growth and parasitic weeds Phytohormones generated by bacteria can be taken up by plants leading to an increase in hormone levels in these plants (Idris et al., 2007) The bio-agents naturally present in soil are usually in low population thus increasing its population density through artificial inoculation is necessary to achieve successful control of target weed Zhen et al., (2014) reported that compost alone or in combination with bacteria fertilizer enhances soil enzyme activities, increase soil respiration rate and cultivable microorganisms whereas chemical fertilizers degrade the activities of soil enzymes The objective of this study was to investigate the effects of Trichoderma harzianum fungi, bacterial strains and compost on Striga hermonthica incidence on sorghum plants Materials and Methods A series of laboratory and greenhouse experiments were conducted at the Environment, Natural Resources and Desertification Research Institute (ENDRI), National Centre for Research (NCR) and College of Agricultural Studies, Sudan University of Science and Technology (SUST), Sudan Laboratory and greenhouse experiments were arranged in a Randomized Complete Design (RCD) and a Randomized 196 Int.J.Curr.Microbiol.App.Sci (2019) 8(3): 195-206 Complete Block Design respectively, with four replicates (RCBD), Laboratory experiments S hermonthica seeds conditioning and germination S hermonthica seeds were collected from sorghum field in Sinnar State, Sudan in 2015 The seeds were sterilized and conditioned as described by Ahmed et al., (2013) The sterilized discs, placed in cm petri dishes lined with filter paper (Whatman No.1), were moistened with 5ml of distilled water, nutrient broth medium inoculated or un-inoculated with respective microbial strains or compost (plant material) About 25-50 surface disinfected S hermonthica seeds were sprinkled on each of the glass fiber discs in each Petri dish The dishes were sealed with parafilm, placed in black polythene bags and incubated at 30°C in the dark for 10 days For germination, each disc was treated with20µl of GR24 at 0.1or 0.01ppm, then the seeds were re-incubated in the dark at 30°Cand examined for germination 24h later using a stereomicroscope as described by Gafar et al., (2015) Microbial inoculum preparation T harzianum was obtained from Faculty of the Agriculture, Omdurman Islamic University T harzianum cultured on Potato Dextrose Agar medium (PDA), amended with 0.05g/l chloramphenicol and stored in the refrigerator at 4°C for further examination The fungus was mass cultured aseptically in 90mm diameter Petri dishes containing 15ml of autoclaved PDA medium The plates were incubated in the dark at 28°C for days On the seventh day, spore suspensions from the fungal inoculum was prepared by flooding the surface of the agar slant with 10ml sterile distilled water and the culture surface gently scraped to dislodge the spores The spore suspension derived from one Petri plate, was transferred to 500ml flask containing 200ml sterile distilled water Flask was shaken for minutes to ensure that the spores were properly mixed Three concentrations of the fungal strain (spore) were prepared (75, 50 and 25%) The fungal spore count for fungal strains was determined with a haemocytometer, so that the final counts were 0.58 x107 spore/ml The combination of Flavobacterium and Bacillus megatherium var phosphaticum (BMP) strains cultured in meat extract agar medium, was obtained from Biofertilizers and Biopesticide Department, ENDRI, NCR Effects of T harzianum culture age on S hermonthica germination The T harzianum was grown in 90mm Petri dishes containing PDA medium at 28°C for 7days Autoclaved Erlenmeyer flasks (500ml) containing 250ml PD broth were inoculated with 8ml mycelium plugs of the fungus The flasks were incubated under shaking at 28°C in a growth chamber for 10, 15, 20, 25 and 30 days S hermonthica seeds were treated with each T harzianum culture, then the seeds were incubated for 10days in the dark at 30°C GR24 (0.1ppm) was applied to each disc then re-incubated for 24h and examined for germination using a stereomicroscope Distilled water and PD broth medium were used as control for comparison Effects of T harzianum culture, culture filtrate, sterilized culture and application time on S hermonthica germination Three T harzianum inoculum types (culture, filtrate culture and sterilized culture) were used in this experiment Inoculums were prepared by adding 8ml mycelium plugs of the fungus to sterilized Erlenmeyer flasks 197 Int.J.Curr.Microbiol.App.Sci (2019) 8(3): 195-206 (500ml) containing 250ml PD broth, then incubated under shaking at 28°C for 10days After incubation time, the filtered inoculum was prepared through a sterile glass funnel (pore 100µM), while the sterilized inoculum was made by autoclaving the culture at 121oC and 15ib/inch2 for 30min The inoculums were added to S hermonthica seeds and incubated for 0, 3, and days GR24 (0.1ppm) was applied to S hermonthica seeds and re-incubated for 24h and examined for germination by using a stereomicroscope (as described by Gafar et al., 2015) Distilled water and PD broth medium were used as control for comparison Effects of T harzianum ethyl acetate extract and application time on S hermonthica germination (during conditioning) T harzianum growth in PD broth was extracted using ethyl acetate solvent Then the extraction was diluted to four concentrations (25, 50, 75 and 100%) Striga seeds conditioned in ethyl acetate extracts were incubated for 3, and days Distilled water and ethyl acetate were used as control Germination bioassays were performed as described previously (Gafar et al., 2015) Effects of T harzianum inoculums persistent on S hermonthica germination This experiment was conducted to study the effect of T harzianum inoculums (culture, sterilized culture and filtrate) and incubation period (2 and hours) on Striga germination The inoculums were prepared as described previously S hermonthica seeds were treated with GR24 at 0.1ppm and incubated for and hours Then T harzianum inoculums were applied to S Hermonthica seeds, re-incubated 24h and examined for germination Distilled water and PD broth medium were used as control Effects of T harzianum, bacterial strains and compost on S hermonthica germination This experiment was conducted to investigate the effects of T harzianum fungi, bacterial strains and compost on S hermonthica germination The fungal culture was prepared as described above Bacterial strains (BMP+Flavobacterium) were grown in 90mm Petri dishes containing meat extract medium incubated at 30°C for 2days Two concentrations of the compost aqueous extract, 50 and 100%, were prepared S hermonthica `seeds were treated with the fungi, bacterial strains or compost extracts either alone or in combinations The treatments were incubated for 10 days GR24 (0.1ppm) applied to S hermonthica seeds and re-incubated 24h and examined for germination as described above Distilled water, PD and meat extract broth media were used as control for comparison Greenhouse experiment This experiment was conducted to study the effects of T harzianum, bacterial combination (BMP+Flavobacterium) and compost on S hermonthica incidence and sorghum performance Plastic pots (19cm diameter), with drainage holes at the bottom, were filled with soil mixture (7Kg/pot) of river silt and sand (1:1v/v) Artificial infestation of soil was accomplished by mixing S hermonthica seeds (1g) with 1kg soil, S hermonthica infested and uninfested controls were included for comparison Sorghum bicolor seeds (5/pot) were sown at 2cm soil depth The pots were subsequently irrigated every days S bicolor seedlings were thinned to plants per pot after weeks of sowing Five grams of T harzianum inoculum carried on rice were added in each pot at sowing where applicable Five milliliters per plant of bacterial combination (BMP+Flavobacterium) broth was inoculated to seedlings after thinning where applicable Fifteen grams per pot of compost were added to the pots before sowing where applicable 198 Int.J.Curr.Microbiol.App.Sci (2019) 8(3): 195-206 Data collected for S hermothica emergence were measured at 2, 4, and weeks after sowing (WAS) and dry weight Data collected for sorghum growth were plant height (at 2, 4, and WAS), shoot and root dry weight Statistical analysis Prior to analysis data on percentage (germination) were arcsine transformed, data on S hermonthica emergence and dry weight were square root transformed to fulfill ANOVA requirements The analysis were performed across experiments using Microsoft Excel Means separations were made by the LSD at 5% Effects of T harzianum inoculum types and application time on S hermonthica germination All types of inoculums significantly (P≤0.05) reduced germination when applied at and 9days (Table 3) Generally, application of T harzianum culture filtrate gave the highest reduction on germination as compared to control and other types of inoculum, it significantly (P≤0.05) inhibited germination by 68, 54 and 46% when applied at 3, and 9days as compared to medium control Effects of T harzianum inoculum extracted by ethyl acetate and application time on S hermonthica germination Results and Discussion Effects of T harzianum culture age on S hermonthica germination Results presented in table elucidate that the germination of S hermonthica seeds increased by increasing T harzianum culture age The highest significant (P≤0.05) inhibition on germination obtained by 10 days culture as compared to both controls Effects of T harzianum aqueous extract on S hermonthica germination The results in table show that application of all T harzianum aqueous extract concentrations significantly (P≤0.05) reduced S hermonthica seed germination during and after conditioning in response to GR24 (0.1 and 0.01ppm) as compared to the corresponding control There were no significant differences in germination between different concentrations T harzianum aqueous extract 100% induced germination during and after conditioning by 64 – 33% respectively, in response to GR24 (0.1ppm) All concentrations of T harzianum inoculum extracted by ethyl acetateat all application times significantly (P≤0.05) reduced S hermonthica germination as compared to the controls (Table 4) The increasing of application time reduced S hermonthica germination Application of T harzianum extract concentrations (100, 50 and 75%) at 9days gave the highest inhibition on S hermonthica germination by 97, 95 and 94%, respectively Effects of T harzianum inoculums persistent on S hermonthica germination All inoculum types applied at and hours after incubation significantly (P≤0.05) reduced S hermonthica germination as compared to the medium control (Table 5) Application of the types of inoculums at hours reduced germination more than at hours Filtrate and culture inoculum at hours reduced germination by 79 and 68%, respectively Effects of T harzianum, bacterial strains and compost on S hermonthica germination The results in table 6, show that all treatments significantly (P≤0.05) reduce S hermonthica 199 Int.J.Curr.Microbiol.App.Sci (2019) 8(3): 195-206 germination as compared to the corresponding control, except compost extract 50% concentration The combination of compost 100%+ T harzianum + BMP+Flavobacterium gave the highest germination reduction by 68%, followed by compost 100%+BMP+Flavobacterium which reduced germination by 60% control (Table 9) T harzianum alone or in combination with compost increased sorghum root dry weight insignificantly as compared to the control Application of the combination of compost with T harzianum and with BMP+ Flavobacterium significantly (P≤0.05) reduced S hermonthica dry weight as compared to the control Greenhouse experiment Parasitic weeds can be controlled either by preventing seed germination or enhancing germination in the absence of host plants, a phenomenon commonly referred to as inefficient germination (Rubiales and Fernández-Aparicio, 2012) Effects of compost, T harzianum and bacteria on S hermonthica emergence Results showed that at weeks after sowing application of BMP+ Flavobacterium alone or in combination with compost and T harzianum alone significantly (P≤0.05) reduced S hermonthica emergence as compared to the control (Table 7) At 4, and WAS the combination of compost with T harzianum and with BMP+ Flavobacterium gave an insignificant reduction onS hermonthica count The overall mean showed that the lowest number of S hermonthica emergence was obtained by the combination of compost plus BMP+ Flavobacterium Effects of compost, T harzianum and bacteria on sorghum plant height Application of all treatments gave an insignificant effect on sorghum plant height (Table 8) The overall mean showed that the highest sorghum height was obtained by the combination of compost plus BMP+ Flavobacterium Effects of compost, T harzianum and bacteria on sorghum and S hermonthica dry weight The combination of compost with T harzianum and with BMP+ Flavobacterium increased sorghum shoot dry weight insignificantly as compared to the infested Results of laboratory experiments in this study revealed that application of all T harzianum aqueous (types) and ethyl acetate extracts concentrations significantly (P≤0.05) reduced S hermonthica seed germination during and after conditioning in response to GR24 (0.1 and 0.01ppm) as compared to the corresponding control The increasing of application time reduced S hermonthica germination The highest significant (P≤0.05) inhibition on germination was obtained by 10 days old culture as compared to both controls This can be attributed to the toxic secondary metabolites which are commonly implicated in the biocontrol activity of soil borne microorganisms (Kumar et al., 2014) Application of T harzianum culture filtrate gave the highest reduction on germination as compared to control and other inoculums All inoculum types (filtrate, culture and sterilized) applied at and hours significantly (P≤0.05) reduced S hermonthica germination as compared to the medium control Filtrate and culture inoculum at hours reduced germination by 79 and 68%, respectively This may be possibly be due to production of a range of toxic secondary metabolites, including gliovirin, gliotoxin, viridian, and viridiol, of which viridiol is strongly 200 Int.J.Curr.Microbiol.App.Sci (2019) 8(3): 195-206 phytotoxic by Trichoderma spp (Jones and Hancock, 1987) Some Trichoderma spp also possesses a high level of rhizosphere competence (Harman, 2000) Mabrouk et al., (2014) reported that living and heat-kill cells of the Rhizobium leguminosarum strain P.SOM induce in pea roots systemic resistance to infection by Orobanche crenata In addition the combination of compost extracted at 100%concentration + T harzianum + BMP+Flavobacterium gave the highest Striga seeds germination reduction (68%), followed by compost 100%+BMP+Flavobacterium (60%) Lowest number of S hermonthica emergence was obtained by the combination of compost plus BMP+ Flavobacterium Application of the combination of compost with T harzianum and with BMP+ Flavobacterium significantly (P≤0.05) reduced S hermonthica dry weight as compared to the control Hassan et al., (2009) reported that some bacterial isolates and strains have both detrimental and positive effects on Striga control and sorghum growth Table.1 Effects of T harzianum culture age on S hermonthica germination T harzianum culture age Water (control) Medium (control) 10days 15 days 20 days 25 days 30 days LSD Germination (%) 70.72* (88.64)** 62.81 (79.03) 33.98 (31.30) 34.33 (31.94) 38.97 (39.60) 45.92 (51.59) 45.27 (50.47) 6.73 *Data out of brackets are arcsine transformed for analysis **Data between brackets are original data Table.2 Effects of T harzianum aqueous extract on S hermonthica germination T harzianum aqueous extract conc 0% (water) GR24 25% 50% 100% LSD T harzianum aqueous conc LSD GR24 LSD Interaction 0.1 0.01 0.1 0.01 0.1 0.01 0.1 0.01 Germination % After conditioning During conditioning 75.20* (93.43)** 90.00 (100.00) 58.51 (72.48) 69.51 (85.97) 49.48 (56.98) 81.30 (91.86) 44.41 (48.98) 55.16 (67.23) 41.25 (43.49) 56.94 (69.72) 42.43 (45.59) 57.96 (71.13) 35.32 (33.76) 55.58 (67.34) 35.07 (33.32) 55.97 (68.45) 5.66 6.78 4.38 5.25 9.80 11.74 *Data out of brackets are arcsine transformed for analysis **Data between brackets are original data 201 Int.J.Curr.Microbiol.App.Sci (2019) 8(3): 195-206 Table.3 Effects of T harzianum inoculum types and application time on S hermonthica germination Time (days) Water 67.35* (85.14)** 68.06 (85.83) 64.27 (81.11) 67.77 (85.59) LSD Inoculum type LSD Time LSD Interaction Medium 59.14 (71.88) 65.23 (82.07) 56.84 (69.80) 57.23 (70.29) Germination (%) T harzianum inoculum type Sterilized culture Culture Culture filtrate 43.06 (46.70) 50.81 (60.03) 47.74 (52.62) 49.43 (57.60) 47.81 (54.85) 30.50 (26.26) 35.08 (33.05) 41.28 (43.68) 33.74 (32.07) 56.04 (68.59) 46.42 (52.47) 37.57 (37.76) 6.10 5.46 12.20 *Data out of brackets are arcsine transformed for analysis **Data between brackets are original data Table.4 Effects of T harzianum inoculum extracted by ethyl acetate and application time on S hermonthica germination Time (days) Water * 73.00 (91.21)** 70.87 (88.66) 70.60 (88.79) LSD Extract LSD Time LSD Interaction Ethyl acetate 70.60 (88.56) 66.11 (83.39) 65.19 (80.45) Germination (%) T harzianum extract conc 25% 50% 75% 36.09 26.28 22.89 (34.72) (20.06) (15.31) 33.16 18.57 16.88 (8.55) (30.19) (10.73) 26.04 11.58 (4.09) 12.51 (4.81) (19.63) 19.66 13.90 34.06 100% 23.84 (17.13) 23.31 (16.36) 8.98 (2.44) *Data out of brackets are arcsine transformed for analysis **Data between brackets are original data Table.5 Effects of T harzianum inoculums persistent on S hermonthica germination Time (h) Water 68.94*(85.46)** 75.58 (93.49) LSD Inoculum type LSD Time LSD Interaction Germination (%) Medium T harzianum inoculum type Sterilized Culture Culture culture filtrate 57.91 (69.14) 48.03 (55.24) 28.02 (22.42) 21.99 (14.44) 75.22 (91.37) 60.44 (75.17) 56.48 (69.30) 50.09 (58.73) 3.64 2.82 8.92 *Data out of brackets are arcsine transformed for analysis **Data between brackets are original data 202 Int.J.Curr.Microbiol.App.Sci (2019) 8(3): 195-206 Table.6 Effects of T harzianum, bacterial strains and compost on S hermonthica germination Treatment Germination (%) 68.05* (84.87)** Water 65.01 (81.96) Medium (PD broth) 62.77 (78.82) Medium (Meat extract broth) 67.99 (85.81) Compost 50% 53.39 (64.40) Compost 100% 51.06 (60.40) Compost 50%+ T harzianum 38.11 (38.14) Compost 100%+ T harzianum 42.77 (46.21) Compost 50%+ Bacteria# 35.06 (33.16) Compost 100%+ Bacteria 47.57 (54.47) Compost50%+T harzianum + Bacteria 30.61 (26.24) Compost 100%+ T harzianum + Bacteria LSD 7.65 *Data out of brackets are arcsine transformed for analysis # **Data between brackets are original data Bacteria = BMP+Flavobacterium Table.7 Effects of compost, T harzianum and bacteria on S hermonthica emergence Treatments Compost 0g/pot Microbe 1.98*(4.50)** Without 1.00 (0.75) T harzianum 0.97 (0.50) BMP+Flavobacterium 1.70 (2.50) 15g/pot Without 1.13 (1.00) T harzianum 0.93 (0.50) BMP+Flavobacterium LSD Compost 0.56 LSD Microbe 0.68 LSD Interaction 0.96 * Indicates square root transformed data (√x+0.5 x: variable) **Data between brackets are original data Striga count Time after sowing (weeks) 3.32 (11.25) 5.13 (28.25) 3.18 (10.75) 5.33 (28.25) 3.27 (10.75) 5.12 (26.25) 3.25 (10.50) 4.94 (24.50) 2.60 (6.75) 4.49 (20.75) 2.65 (7.25) 4.52 (20.50) 0.81 0.96 1.00 1.17 1.41 1.66 Mean 4.77 (26.25) 4.95 (24.25) 4.60 (21.25) 4.52 (20.75) 4.37 (21.00) 3.66 (13.25) 1.17 1.44 2.03 Table.8 Effects of compost, T harzianum and bacteria on sorghum plant height (cm) Treatments Compost Microbe Control (without Striga) 0g/pot Without T harzianum BMP+Flavobacterium 15g/pot Without T harzianum BMP+Flavobacterium LSD Compost LSD Microbe LSD Interaction Plant height (cm) Time after sowing (weeks) 23.95 36.00 44.25 44.88 21.58 29.40 30.75 35.10 15.60 29.45 28.05 29.30 17.23 29.55 28.90 32.68 20.98 26.95 27.63 34.63 22.23 32.65 31.30 31.78 18.73 33.55 33.47 34.90 4.98 5.24 6.95 6.87 6.09 6.42 8.51 8.42 8.62 9.08 12.04 11.90 203 Mean 36.68 29.80 25.60 27.09 27.54 29.49 30.16 17.56 16.00 14.69 14.56 12.38 10.38 Int.J.Curr.Microbiol.App.Sci (2019) 8(3): 195-206 Table.9 Effects of compost, T harzianum and bacteria on sorghum and S hermonthica dry weight Treatments Microbe Compos t Control (without Striga) 0g/pot Without T harzianum BMP+Flavobacterium 15g/pot Without T harzianum BMP+Flavobacterium LSD Compost LSD Microbe LSD Interaction Dry weight (g) Sorghum shoot Sorghum root 82.50 34.25 49.00 43.50 34.50 51.75 51.00 25.90 31.73 44.87 111.75 63.50 100.25 68.50 92.25 123.25 64.75 57.68 70.64 99.91 Striga // 3.30* (10.50)** 3.23 (10.50) 3.03 (8.75) 3.95 (15.25) 2.93 (8.50) 2.54 (6.50) 0.55 0.68 0.96 * Indicates square root transformed data (√x+0.5 x: variable) **Data between brackets are original data Auxins are also associated with strong inhibition to Striga attachment and haustorium development because of their antagonistic nature with cytokinins and benzoquinone, both of which favor attachment and haustorium development (Keyes et al., 2000) wheat (Triticum aestivum) growth following improvement of the plant’s IAA and cytokinins pool by PGPR Additionally, application of exogenous cytokinins have been found to increase plant height, nitrogen, phosphorus and potassium uptake and total biomass in rice (Zahir et al., 2001) Cytokinins are known to boost chlorophyll production which is an indication of sorghum plants’ improved capacity to fix carbon hence the increase in biomass observed in Strigafree sorghum plants The highest sorghum height was obtained by the combination of compost plus BMP+Flavobacterium Hameeda et al., (2006) reported that Plant Growth Promoting Rhizobacteria (PGPR) stimulated germination and promoted plant growth and their application with composts synergistically enhanced plant growth Such PGPB can be applied as additional inoculants along with composts and make a synergistic treatment for improving plant growth Since Striga infection lowers IAA levels in hosts (Press et al., 1999) and auxins such as Indole Acetic Acid (IAA) are thought to inhibit Striga germination (Miché et al., 2000), Bacillus strains could offer growth benefits to sorghum and suppressive effect on Striga due to their IAA producing ability For instance, Hussain and Hasnain (2011) reported an increase in The combination of compost with T harzianum and BMP+ Flavobacterium increased sorghum shoot dry insignificantly as compared to the infested control T harzianum alone or in combination with compost increased sorghum root dry weight insignificantly as compared to the control Application of composts with bacterial strains improved plant growth up to 88% These results confirm the synergistic effect of bacteria and fungi applied with compost on growth of pearl millet reported by (Hameeda et al., 2006) In this context Zafar-ul-Hye et al., (2015) recorded that Pseudomonas 204 Int.J.Curr.Microbiol.App.Sci (2019) 8(3): 195-206 bacterial strains improved maize root and shoot length and dry weight Satyavani, K 2006 Application of plant growth-promoting bacteria associated with composts and macrofauna for growth promotion of Pearl millet (Pennisetum glaucum L.) Biol Fertil Soils, 43: 221–227 Harman, G.E 2000 Myths and dogmas of biocontrol Changes in perceptions derived from research on Trichoderma harzianum T-22 Plant Disease, 84: 377–393 Hassan, M.M., Abdelgani, M.E and Babiker, A.G.T 2009 Potential of bacteria strains and nitrogen in reduction of Striga hermonthica (Del.) 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M Hassan, Mona A Azrag, Ahmed M.E Rugheim, Rashida M .A Abusin, Maria H Elnasikh, Hanan I Modawi, Magdoline M Ahmed, Rania A Abakeer, Awad G Osman, Migdam E Abdelgani and Abdel-Gabar E Babiker... *Data out of brackets are arcsine transformed for analysis **Data between brackets are original data Table.2 Effects of T harzianum aqueous extract on S hermonthica germination T harzianum aqueous... 0.96 * Indicates square root transformed data (√x+0.5 x: variable) **Data between brackets are original data Auxins are also associated with strong inhibition to Striga attachment and haustorium